i've already said above it would perhaps present an advantage doing it all on one board or at least well integrated, but when there is already perfectly good solutions designed by others to use with what hes got already, the only reason would be money. I would be extremely surprised if it measured more than 1db better than what is possible already with modules. a proper and original well performing discrete analogue stage isnt a small undertaking either, I would say this is further out of Ians skillset than the USB.

Since you mention him, Lucien and Acko are already working together on a project, which could be interesting. interesting for others that is, i'm about done with dacs for quite a while I think and I cant justify building another one

If I was going to be bold enough to suggest anything to anyone I'd be suggesting that acko made a combo-board with a mounting position for the FIFO board ...

I wonder if everyone has recognised the significance that Ian has provided rubber mounting rings for the FIFO boards to decouple vibration from the clock circuits especially. Any integrated board that uses this decoupling technique will still be using u.fl/w.fl coax connections for moving the i2s between FIFO output and DAC input.

The value (in terms of performance gains) of an integrated DAC design over an acko combo board with FIFO is what exactly?

one thing that could be cool would be a differential clock driver to get rid of the clock/ground connection as well, but any of that will add jitter, in fact pretty much any isolation technique will, so its kinda 6 one way half a dozen the other for any 'improvements' from this point on

If I was going to be bold enough to suggest anything to anyone I'd be suggesting that acko made a combo-board with a mounting position for the FIFO board ...

Another flashing idea! I will move the mounting holes a bit on the next version of FIFO PCB, to make a new possible option: clock board stack above the FIFO board. That will save a lot of space for a DAC project.

Step4: Cut the solder mask paint beside the both GND pads of the header appearing small area of GND copper plate, please be careful no touching any other circuit route.

Step5: Solder the support pads of the header to the appeared GND copper plate. Solder iron with higher power may require. For enough support force, applying compound of strong glue (such as epoxy) is highly suggested for double support.